Bogota , Colombia -LRB- CNN -RRB- -- It 's the largest producer of cocaine in the world and a key supplier of heroin to the United States .

According to the CIA , Colombia produces 535 metric tons of cocaine a year , most of it for the U.S. market . The South American country has retained its status as key cocaine producer in spite of an ambitious anti-drug agreement launched a decade ago with the financial support of the United States .

The agreement is called `` Plan Colombia . ''

Since 2000 , the plan has cost the United States $ 7 billion , according to the Inter-American Dialogue , a Washington think tank that has closely monitored the implementation of Plan Colombia .

The money has been mostly used to help Colombia strengthen its police and military . Before the implementation of Plan Colombia , 50 % of the Colombian territory did n't have a government security presence .

Marta Lucia Ramirez , a former Colombian minister of defense and one of the architects of Plan Colombia , says the agreement has helped her country to strengthen democracy and government institutions . It has also increased the Colombian government 's ability to fight what she calls `` narco-terrorism . ''

But Ramirez also says that the high drug demand in the U.S. makes it difficult to eradicate production at home .

`` I really believe that the American strategy against drugs is not enough . It 's probably a failure . It 's -LSB- a policy -RSB- that they have to review , '' says Ramirez .

Colombia welcomes U.S. drug czar Gil Kerlikowske this week . Kerlikowske , in his role as director of the White House 's Office of National Drug Control Policy , will do a progress evaluation of plan Colombia as part of his trip .

Ahead of his visit , Kerlikowske told the Colombian newspaper El Tiempo that he sees a commitment on the part of the government of President Juan Manuel Santos , who took office in August .

`` We 're going to talk about the continuation of the relationship between both countries , not only in terms of reduction but also in terms of prevention and demand , '' said Kerlikowske .

Security experts , including Colombian Aurelio Suarez , say Plan Colombia has improved security , but it has fallen short on its original goal of reducing drug production in the region . In what is known as the balloon effect , increased army attacks against drug traffickers in Colombia has moved coca and poppy crops elsewhere .

`` And the quantity of the drug production from the Andean countries like Bolivia , Peru and Colombia is the same as 10 years ago , '' says Suarez .

Salud Hernandez , a journalist who has traveled extensively in areas where coca is grown , has witnessed the balloon effect . She says drug traffickers just move to other countries , but also relocate within Colombia .

`` There are still drug dealers -LSB- in Colombia -RSB- . There 's still a lot of drug trafficking , and there are still a lot of crops in many regions of the country , '' says Hernandez .

What 's even more troublesome , the Washington-based Inter-American Dialogue says that roughly 90 % of cocaine sold in the United States still comes from Colombia .

Michael Shifter , the organization 's president , says that `` Plan Colombia 's many critics rightly point to the policy 's failure to meet the fundamental purpose for which the program was developed : To reduce the availability of drugs , particularly cocaine in U.S. communities , '' says Shifter .

In Colombia there 's a new push to refocus government efforts on improving socioeconomic conditions for the population as a means of making organized crime and guerrillas associated with drug traffickers less appealing to peasants who live in marginalized areas . Colombia 's problems go well beyond drug trafficking and security .

About 50 % of Colombians live in poverty , and 60 % have no regular employment . Now that security has improved , many Colombians such as security analyst Suarez say it 's time for the Colombian government to address issues such as social inequality and long-term development as a way to slow down the seemingly never-ending production of illicit drugs in Colombia .

@highlight

Since 2000 , U.S. has funded anti-drug initiative `` Plan Colombia '' at cost of $ 7 billion

@highlight

One of the architects of plan points out democracy has been strengthened in Colombia

@highlight

Critics point out that 90 % of cocaine sold in U.S. comes from Colombia

@highlight

U.S. drug czar Gil Kerlikowske will visit this week to check on progress of anti-drug effort